I have one of Addax's first piston uppers that I bought several years ago at the SAR show.It is a ASA sidecharging upper with a fluted 16 inch SS barrel.I love the rifle .I had an easy 2000 rounds through it,Then it started to function like a bolt action. So I called up Chris to see if he could take a look at it,Hoping He would not charge and arm and leg to fix it. He said bring it by.So I drove about an hour to his shop. He took the rifle and about hour later he give back to me. he even test fired it. Well took it to the range finally the other day ,It shoots great. My hats off to Chris at Addax .He is the man.That is what I call great customer service.